Improvement in clamp-mills for turning metals



W. H. BRAINARD.

Improvement in Clamp-Mills for Turning Metais.

No.129,092. Patented uly 16,1872.

Wifless as:

UNITED STATES PATENT OFFICE.

WILLIAM H. BRAINARD, OF BRANFORD, CONNECTICUT.

IMPROVEMENT IN CLAMP-MILLS FOR TURNING METALS.

Specification forming part of Letters Patent No. 129,092, dated July 16, 1872.

Specification describing an Improvement in Clamp-Mills for Turning Metals, invented by WILLIAM H. BRAINARD, of Branford, in the county of New Haven and State of Connecticnt.

it has to be recut by a cherry, preparatory to which it is requisite to previously anneal the block, which, by repeated annealing and rehardening, has'the quality of the steel so impaired as to render it worthless. The object of this invention is to obviate the necessity of grinding away the mill and consequent reduction of the cavity; and to this end the invention consists in novel combination and arrangement of an adjustable and removable cutter, secured by a clamp, and main blocks or clamps, so that when the edge of the cutter is blunted it may be removed and ground without drawing the temper, and afterward replaced and adjusted.

In the accompanying drawing. Figure 1' is a transverse section of a clamping-mill constructed according to my invention. Fig'2 is a plan of the same, and Fig. 3 is a face view of one of the mills.

Similar letters'of reference indicate corresponding parts in all the figures.

A and B are the two mills, the latter of which is of ordinary construction, and the former is formed in the usual way, except one side is planed ofi to the edge of its cavity a, leaving no face on that side of the latter. C is the adjustable and removablecutter, consisting of a piece of hardened and tempered steel plate, which fits against the planed-off side of the mill A, and is ground at its outer edge to a suitable bevel. The inner face of this cutter, which is placed next the mill, is made to correspond, like the bottom of the cavity of the mill, with the longitudinal profile of the article to be produced. D is a clampingplate, which bears against the outer side of the cutter C, and, by means of a screw, E, screwing into a tapped hole in the mill, is made to clamp the latter, and thereby secure it in place. By this means the adjustment of the plate C is provided for. The outer portion of this plate is made to fit the stock in which the mill is secured. When the edge of the mill-cutter becomes dulledthe clampingplate D is detached and the former removed and sharpened, and afterwards replaced.

Instead of making the'cutter C straight, as

represented, it may be made of the form of a portion of a ring, as it is much easier to turn such a cutter to the requisite profile in a lathe than to plane up a fiat cutter to such profile.

Both mills of a pair may be constructed according to my invention.

Claim.

The combination, with the clamps A B, of the adjustable cutter C and its clamp D, all arranged as shown and described, for the pur- 

